Centrifugal pumps



T. E. JUDD CENTRIFUGAL PUMPS Filed Sept. 13, 1963 June 22, 1965 INVENTOR.

THOMAS E. JUDD IS ATTORNEY United States Patent O 3,190,226 CENTRIFUGAL PUlVIPS Thomas E. Judd, 1960 Browning Ave.,

Salt Lake City, Utah Filed Sept. 13, 1963,Ser. No. 308,791 6 (Zlaims. (Cl. 103103) The present invention relates to centrifugal pumps and, more particularly, to improvements in centrifugal pumps which are useful in connection with the pumping of liquids having solids mechanically entrained therein, sewage and slurries being examples.

In the past a great many types of centrifugal pumps have been designed to function in various contexts. Those centrifugal pumps of which the inventor is aware appear to be deficient in certain respects, howe er, wherein intended usage is that of pumping liquids having mechanically entrainedsolids, such as sewage and slurry liquids. Present centrifugal pump designs, when used in such contexts, appear to have disadvantages in undesired flow characteristics, in impeller'vane wear and, indeed, in clogging the impeller with such stringy material as may be present in the liquid, in the course of pumping operation. In connection with the latter objection, conventional pumps require a large clean-out port, not needed in the present invention, which clean-out port in conventional designs is proximate the impeller and is necessitated for cleaning the impeller area. Further, present designs of impeller vanes themselves have been such that, heretofore, they have been positioned at a direct or proximate impact areaso that hard, solid granuleswill directly impinge upon the leading edges of the blade and cause the latter to become subject to excessive wear in ashort time. Furthermore, present vane designs for conventional pump impellers provide reduced passage for the liquid being pumped and offer excessive obstruction areas which tend to impede complete flow.

Accordingly, a principal object of the invention is to provide a new and improved centrifugal pump wherein the impeller thereof provides increased throat or passageway from the inlet orifice along and adjacent the impeller to the outlet orifice of the pump.

A further object of the invention is to provide in a centrifugal pump an improved impeller having a front face of general convex character, the front face serving Patented June 2 2, 1965 vane -means on the front face of an impeller in such a to reduce turbulence thereat, thereby increasing pumping efficiency, and, further, permitting solid objects impinging thereon to advance outwardly in the most optimal manner.

A further object of the invention is to provide in a centrifugal pump an impeller having a convex front face wherein a central portion of the face is free of vane protrusions, thereby permitting solids to impinge upon the impeller face and to be thrown radially outwardly withoutchance of interference with the .vanes or of producing damage to the vanes.

A further object of the invention is to provide in a i" centrifugal pump an impeller having a convex front face, wherein the centrifugal pumping vanes of the impeller are mutually spaced from a central area of the face of the impeller, and wherein the vanes form smooth junctures with the impeller face so that stringy material, for exmanner that greatest pumping action is obtained proximate the periphery of the impeller, but with the face thereof being substantially unobstructed, thereby insuring a maximum throat or passageway for liquid passing between the impeller and the housing of the pump; for

greatest efiiciency and to reduce passageway obstruction,

it is desired that the secondary vanes have girths or heights less than those of the primary vanes on the front face of the impeller. I

A further object is to provide an impeller wherein the pumping action thereof is substantially obtained along the periphery of the impeller. i

A further object is to provide vanes onboth faces of a centrifugal pump impeller, with the vanes on the rear face being so disposed, and the character of the rear face being such that minimal protrusion of the rear vanes is "obtained, thereby facilitating a close mounting of the re of the impeller'to the housing of the pump. Y Y

A further object of the invention is to provide a cantrifug'al pump impeller wherein the leading edges ofthe 'vanes thereof are prevented from protruding forwardly as their extremities are approached; rather, it is important that the vanes be normal to the irnpeller'axis or, and preferably, sloped rearwardly so that solids build-up impeller vanes is avoided.

A further object is to provide a centrifugal pump wherein no clean-out facility is needed to clean the pumps impeller.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings in which:

FIGURE 1 is a vertical section taken along the line 11.in FIGURE 2 and shows the basic features of the invention; the circles indicated, a representative one of,

which" is designated S in FIGURE 1, illustrate the largest possible mechanically-entrained solid objects which the centrifugal pump shown can accommodate. 50 i of the present invention shown in FIGURE 1.

FIGURE 3'is a front elevation of the novel impeller FIGURE 2 is a front elevationof the centrifugal pump of the invention.

FIGURE 4 is an elevation of the rear face of the peller shown in FIGURE 3.

i FIGURE 5 is an enlarged, fragmentary section of a portionof the impeller of thepresent invention,'showing the contour of vane junctures with the impeller base, and illustrates the important feature that the leading edges of the front vanes of the impeller are at least parallel to and preferably slope rearwardly from an imaginary plane 'normalto the impeller face and intersecting the impellers axis of rotation.

In FIGURE 1 housing structurelfl includes a conically shaped housing bell 11 and housing back plate 12, this structure being secured together ,by bolts 13 incooperation with sealing gasket 14. The housingstructure is shown .to include .an inlet orifice 15 'which,'by reason} I of the inclusion of attachment flange 16, may be coupled to an external source of liquid. Exhaust orifice17 is provided'as a side aperture having communication with external conduit 18, the latter provided with attachment flange 19.-

An impeller 20 of unique design is fixedly secured .to impeller shaft 21 as by keying, a press fit, or other suitable means, and is journaled and sealed by packing gland .22, a the latter being'positioned ,in' gland mounting portion 23 of the housing structure wand being secured and placed by packingretainer nut 24 which, upon positioning is re tained in place by set screw 25 p I p Essential limitations of the impeller are that it have a convex front face26 and that it be provided with plural convex front face, which is, convex toward intake orifice 15. Not considering the several vane-s for the moment,

,it will be understood that the impeller 20 is preferably a geometric object of revolution the front face 26 of'which' may be thought of as being generated by circular, .elliptical, 'parlaboloid, or hyperboloid line segment generated about the axis 32 and rectilinear axis 33, the two axes coinciding in being-the axes of impeller. shaft 211 and im- 7 peller 20, re-sectiv'ely. Other types of line segmentsgenvanes 27 which, in a preferred form of the invention,

comprises'respective sets of vane-s 27A and 27B. The

several radial vanes27 (sets 27A and 27B) are mutually spaced withrespect to each othensee FIG. 3,"'and are preferably regularly spaced as shown, The vanes 27B .are primary vanes which preferablyextend to the periph ery 28 of base 29 of the over-all impeller 29. Varies 27A are auxiliary vanes Which add to the centrifugaliforce produced by vanes 273 at the impeller periphery and," hence, to the pumping action of the impeller. It is to be noted in connection with the drawings that thesecondary vanes 27A, in addition to being shorter than primary ivanes 27B, also are'reduced in height (i.e., width). when compared, point by point along" concentric circles, with primary vanes 2713p See FIGURE 1. This is for the purpose of supplying flow paths for entrained solids which are relatively unobstructed, save'for the slight protrusions of the upstanding secondary vanes 27A and the widely spaced, primary vane-s 27B- It is also noticed that thevanes 27 are mutually spaced apart not only among themselves but also from the center C of the impeller base 29. This provides a certain' solidsimpact area 30 of general disc form which receives impact forces ther'eon as produced by entrained solids impinging secting axis 32 .of shaft 21 (and rectilinearly related axis 33 of the impeller 20), then it is seen that the face 26, in being convex, gradually falls away, from imaginary plane 33 as farther distances from the center 1C are reached. V i l y Consider asecondary one of (here) coplanar imaginary planes 37 (see againFIGURE 5)' which is normal to the plane of thepaper and parallel to plane 33 and, further, which intersects the juncture of the leading edge 38, of a erated 360 about axes 3-3 and 3-2 may also be used such."

as a compound curve, for example,fprovided, however,

a that the over-all'front'face con-tour is in a general convex 'configurernent, .thatis, allsurfiacenQrmalsN to face 26 do not diverge. V g

. In a preferred form of the the impeller 2% includes a'concave rear face 34 upstanding from which are plural vane=means 35 comprising a plurality of rearwardly facing, upstanding vanes36 this construction insures that the impeller 20 might be pl-aced as I close as possible to housing'back plate 12. Thus, it'is'seen to be desirable that'the several rearwardly facing upstanding vanes 36 be contained within the general dish-configured eoncavity 37 as is formed the rear face 34and outer periphery28 of the impeller 20 proper. These vanes 36 may be relievedvat in airegula r manner as is necessary to accommodate clearance for gland mounting portion 23 of the housing backplate. 12.5 Of special importance'in the invention is that the: pumping actionofthe rear'vanes 36 be greater'thanathe pumpingaction of the vanes 27 '(27Aand 27B) upstanding from the front face 26 of the impeller 20. This isto assure that there will be no leakage problem whatever at the packing plant 22and,

further, and more important, so that gritty material in the fiuidmedium being pumped will not tend to work its Way up into the interiorof the structure as;in a direction R. Through experimentation the inventor has discovered that when the pumping action of the rear vane36-exceeds that 10f theplural front vanes 27, then the packing gland 22 L can even beremovedwhile the pump is being operated .without any leakage being present. Hence, there is aS- -sured an important feature of, the invention wherein, in loperatiomithe apparatus keeps the pumped media from collecting rearwardly of the impeller 20. Y

Injreased' pumping'action: of the rear vane means 35 over the front plural vanes 27 may be obtained by ap proprlately designing the individual vanes relative .tothe respective impeller faces26 and 34. It is well known in the art that pumping-action increases as vane areaiincrea-ses'and as the-distance of the vane from the impellers I center of rotation isfincr'eased. In the example given'in. FIGURE 1, increased vane area of the rearwardly facing; I

efiect.

-van'e means 35 is relied upon to produce a pumping greater than that of the front vanes-27. f

The pump shown in FIGURE 1 operates as follows.

Motor M is direotly coupled-to impeller shaft'21 to rotate i the same; A liquid-carried, mechanically-entrained solid particular radial vane 27B .(or 27A with front fiace 25.:

Now if there is drawn a line 38' to juncture 31 tangent to face 26, which tangent line 38 is in the same plane as the proximate portion 40 of the leading edge 38 of Vane 27B (or 27A), then the juncture angle A is' seen to be greater than juncture angle B, that is, the angle betweennormal preferably, greater than juncture angle B. This isaso that "stringing sewage matter, for example, which maybe present in the liquid source will not tend to pile up at juncture 31, but rather w'ill easily slide down the leading edge 38 of any of the plural vanes 27 (that is, 27A or 27B). 7 It will be-nnde'rstood that, as seen in FIGURE 1, the. limitation'for juncture angle of the leading edges of the vanes will apply to all blades whereverssituated on the front face .gof theiimpeller.

The impeller 20 itselfhas been described as having a 7 plane 37 and tangent line 38' in the plane of the paper.

It is essential that juncture angle A be equal t enters intake orifice 15; theliquid phase is automatically directed along a generally comically-configured, pumped media passageway 41 in thedirect-ion of arrows L. Since. the front face 26 being convextowards the source of the fluid, fluid turbulenc'eiat the central area 30 of the front.

face is reduced to a minimum. This is desirable from'an "effic'iency point of view' and for obtained desirable flow patterns. 7

- 'Entrained solids impingeiupon the. solids-impact area,

30, see FIGURE 3,. and friction and impact with the revolvingfa'ce 2 6 urges the solids s upwardly and directly along the. front face. Liquid flow tends to keep the solids against the front face as they proceed outwardly there-j along. Now it is desired that the pump accommodate :all typesof. liquid media including that wherein solids-'- such as sewage,stringy'matter, and solid particles asin slurries, maybe accommodated. It isdesiredthat the solids have as little contact "with the centrifugal impeller vanes 27A and 27B as possible. Hence, the. solids, by

invention it will be seen'that virtue of liquid pressure intending to keep them against the front face 26, will proceed outwardly along the impeller base 29 at the front face 26 thereon and between the widely spaced vanes 27B. The secondary vanes 27A provide increased centrifugal action at the periphery 28 while not impeding the travel of the solids. In this regard it is eminently desirable to have the girth or height of the vanes retricted as shown in FIGURE 1 so that a generous flow passageway will be presented between the leading edges 38 of vane means 27 and housing and also between adjacent ones of the primary vanes 278. In view of the fact that there is an ample, conicallyshaped, fluid-flow passageway defined by the leading edges of blades 27B and the interior surface 45 of housing bell 11, solid matter will not tend to be impeded in its outward travel toward an annular discharge chamber 46 by the existence of the vanes. Further, it. is important to note that the contour areas at junctures 31 (see FIG- URE 5) of the vanes, both primary and secondary, with the impeller face 26 are such that stringy solid matter, for example, will not tend to cling to or be caught by these junctures. Hence, it is important that the leading edges 38 of the vanes 27B and 27A be such that they be coplanar with or, and preferably, sloped rearwardly with respect to imaginary planes (e.g. 37), parallel to the primary imaginary plane 33 in FIGURE 5, which intersect and are normal to axes 32 and 33. Hence, stringy solid matter will tend to slide off -the leading edges of the vanes 27 (27A and 27B) under the centrifugal action of the pump without chancing any accumulation whatever at the impeller area. Hence, clean-out holes and traps in the design need not be incorporated. Once the liquids and the solids reach the annular discharge chamber at 46, the same are intimately re-combined again, and are urged out of exhaust orifice 17 and hence out conduit 18 as a pump fluid.

It will be noted that the centrifugal pump may be utilized for pumping any type of liquid; however, it is particularly suited for liquids having mechanically entrained solids such as sewage, slurries, mud fluids for drilling, and so forth.

There has been discussed previously the action of the rear vanes 35 in keeping substantially all fluid flow in front of the impeller and permitting the accumulation of no gritty material or other solids rearwardly of the impeller. Indeed, by virtue of the fact. that the pumping action of the rear vanes 35 exceeds that of the front vanes 27, no fluid whatever will accumulate rearwardly "of the impeller so long as the pumpis operating.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes. and modifications may be made without departing from this invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

I claim:

1. In a centrifugal pump including housing structure defining an interior cavity and including a central intake orifice and a side exhaust orifice, and a shaft sealingly journalled to and extending within said housing structure and nominally axially disposed in line with and facing said intake orifice; an improvementcomprising an impeller revolvably disposed in said housing structure and including a base fixedly secured to said shaft, said base having a continuous, convex front face which is spaced from and faces said intake orifice, said shaft having an axis of rotation passing centrally through said front face, said impeller also including plural, radially extending vanes afiixed to said base and upstanding from said front face, said vanes being mutually spaced from each other and from the center of said front face, said vanes having plane normal to and intersecting said shaft axis at its intersection with said front face, said leading edges of said vanes having their respective portions proximate said front face joining said front face in respective contours, to form juncture angles, that is, angles between said proximate portions of respective ones of said leading edges of said vanes and tangents to said front face at said contours which respectively lie in the same planes as said proximate portions of respective, ones of said leading edges of said vanes, said juncture angles of said leading edges with said front face, beingnot less in magnitude than juncture angles between said front face and respective, secondary imaginary planes parallel to said primary imaginary plane and .respectively'intersecting said front face at respective leading edges junctures therewith, and

saidhousing structure and said impeller being so constructed and arranged to provide an annular discharge chamber circumscribing said impeller and communicatingwith said discharge orifice and also to provide an annular, conical, pumped-media passageway interconnecting said intake aperture with said discharge chamber and disposed between said leading edges of said vanes and said housing structure.

2. Structure according to claim 1 wherein said vanes extend to the periphery of said base.

3. Structure according to claim 1 wherein some of said plural vanes are radially shorter than remaining vanes and wherein those of said plural vanes which are radially shorter are also reduced in height when compared, point by point along, concentric circles with said remaining vanes.

4. Structure according to claim 2 wherein some of said plural vanes are radially shorter than remaining vanes, and wherein those of said plural vanes which are radially shorter are also reduced in girth relative to that of the remaining vanes.

5. In a centrifugal pump including housing structure axis of rotation passing centrally through said front face,

said impeller also including plural, radially extending vanes affixed to said base and upstanding from said front face, said vanes being mutually spaced from each other and from the center of said front face, said .vanes having leading edges terminating short of a primary imaginary plane normal to and intersecting said shaft axis. at its intersection with said front face, said leading edges of said vanes having their respective portions proximate said front face joiningsaid front face in respective contours totform juncture angles, that is, angles between said proximate portions of respective ones of said leading edges of said vanes and tangents to said front face at said contours which respectively lie in the same planes as said proximate portions of respective ones of said leading edges of said vanes, said juncture angles of said leading edges with said front face being not greater in magnitude than juncture angles between said front face and respective, secondary imaginary planes parallel to and spaced rearwardly from said primary imaginary plane and respectively intersecting said front face at respective leading edges junctures therewith, and said housing structure and said impeller being so constructed and arranged to provide an annular discharge chamber ci-rcumscribing said impeller and communicating with said discharge orifice and also to provide an annular, conical, pumped-media passageway interconnecting said intake aperture with said discharge chamber, and disposed between said leading edges of said vanes and said housing structure.

orifice and a side exhaust orifice, and a shaft'sealingly journalled to' and extending Within said housing structure and nominally axially disposed in line with and facing said intake orifice; an improvement comprising an impeller. re:

yolvably disposed in said housingstructure and including a base fixedly secured to said shaft, said base having a a continuous, convex frontface which isspaced'fromjaud faces said intake orifice, said shaft having an axis of rotation passing centrally through said front face, said impel ler also including plural, radially extending vanes affixed to said base and upstanding' from said front face, rsaid vanes being mutually spaced from each other and from the centerofsaid front face, said vanes having leading edgessloped rearwardly with respect to the direction in V which said front face is facing, said front face being free of said vanes in a central region the size of which at'least n 4 5 equals the size of said central intake orifice, said central region being nominally in registry with said central intake orifice. f a V References (Iited by the Examiner UNITED STATES PATENTS 1,559,883 11/25 Karr etal; 2,284,141 5/42 Funk 230-434 2,650,755 9/53 Woodward 23a-134 2,699,764 1/55 Kiephaefer 230 1 1 I 3,044,40s 7 /62 a Mellott 103: 103

5 FOREIGN PATENTS 300,040 5/00 France; 1

212,879 of 1925 Great Britain. 1 

1. IN A CENTRIFUGAL PUMP INCLUDING HOUSING STRUCTURE DEFINING AN INTERIOR CAVITY AND INCLUDING A CENTRAL INTAKE ORIFICE AND A SIDE EXHAUST ORIFICE, AND A SHAFT SEALINGLY JOURNALLED TO AND EXTENDING WITHIN SAID HOUSING STRUCTURE AND NOMINALLY AXIALLY DISPOSED IN LINE WITH AND FACING SAID INTAKE ORIFICE; AN IMPROVEMENT COMPRISING AN IMPELLER REVOLVABLY DISPOSED IN SAID HOUSING STRUCTURE AND INCLUDING A BASE FIXEDLY SECURED TO SAID SHAFT, SAID BASE HAVING A CONTINUOUS, CONVEX FRONT FACE WHICH IS SPACED FROM AND FACES SAID INTAKE ORIFICE, SAID SHAFT HAVING AN AXIS OF ROTATION PASSING CENTRALLY THROUGH SAID FRONT FACE, SAID IMPELLER ALSO INCLUDING PLURAL, RADIALLY EXTENDING VANES AFFIXED TO SAID BASE AND UPSTANDING FROM SAID FRONT FACE, SAID VANES BEING MUTUALLY SPACED FROM EACH OTHER AND FROM THE CENTER OF SAID FRONT FACE, SAID VANES HAVING LEADING EDGES TERMINATING SHORT OF A PRIMARY IMAGINARY PLANE NORMAL TO AND INTERSECTING SAID SHAFT AXIS AT ITS INTERSECTION WITH SAID FRONT FACE, SAID LEADING EDGES OF SAID VANES HAVING THEIR RESPECTIVE PORTIONS PROXIMATE AND FRONT FACE JOINING SAID FRONT FACE IN RESPECTIVE CONTOURS, TO FORM JUNCTURE ANGLES, THAT IS, ANGLES BETWEEN SAID PROXIMATE PORTIONS OF RESPECTIVE ONES AND LEADING EDGES OF SAID VANES AND TANGENTS TO SAID FRONT FACE AT SAID CONTOURS WHICH RESPECTIVELY LIE IN THE SAME PLANES AS SAID PROXIMATE PORTIONS OF RESPECTIVE ONES OF SAID LEADING EDGES OF SAID VANES, SAID JUNCTURE ANGLES OF SAID LEADING EDGES WITH SAID FRONT FACE BEING NOT LESS IN MAGNITUDE THAN JUNCTURE ANGLES BETWEEN SAID FRONT FACE AND RESPECTIVE, SECONDARY IMAGINARY PLANES PARALLEL TO SAID PRIMARY IMAGINARY PLANE AND RESPECTIVELY INTERSECTING SAID FRONT FACE AT RESPECTIVE LEADING EDGES'' JUNCTURES THEREWITH, AND SAID HOUSING STRUCTURE AND SAID IMPELLER BEING SO CONSTRUCTED AND ARRANGED TO PROVIDE AN ANNULAR DISCHARGE CHAMBER CIRCUMSCRIBING SAID IMPELLER AND COMMUNICATING WITH SAID DISCHARGE ORIFICE AND ALSO TO PROVIDE AN ANNULAR, CONICAL, PUMPED-MEDIA PASSAGEWAY INTERCONNECTING SAID INTAKE APERTURE WITH SAID DISCHARGE CHAMBER AND DISPOSED BETWEEN SAID LEADING EDGES OF SAID VANES AND SAID HOUSING STRUCTURE. 